Algodoo

Don't let the title fool you! Just because it field strips does not mean it doesn't work well. In fact, out of all three versions I have created, this one works the best. By far. Use it just like you would an M16A2. It has been constructed to function almost the same. To field strip, simply pull the pin holding the upper and lower receiver together back towards the stock. Before doing this, make sure the weapon is safe, the hammer is cocked, and the mag well and chamber are cleared. Once the upper receiver rotates and stops, pull back on the charging handle and remove the bolt.

EDITS: Much more improved selector mechanics were added, as well as some balancing of forces overall. Works much better now.